Method and apparatus for the banding of objects

ABSTRACT

A method and apparatus for securely fastening a band to at least one object such as a refractory nozzle for a molten steel pouring ladle. A tab is affixed to the end of a band and the band is wrapped around the object so as to divide the band into a wrapped section and an unwrapped section, a first portion of the wrapped section overlying the tab and a second portion of the wrapped section. While the tab is restrained against movement in one direction around the object, the unwrapped section of the band is pulled so as to tighten the band around the object. While the band is held in this position, automatic welding means indirectly pressure spotweld the tab and the first and second portions of the wrapped section together.

United States Patent Shotting et al. Aug. 5, 1975 [54] METHOD ANDAPPARATUS FOR THE 2,972,294 2/1961 Lecocq 100/33 R x 3,439,606 4/1969Bursik et al 100/29 x BANDING OF OBJECTS Inventors: Kenneth FredericShotting,

Coraopolis, Pa.; Sidney Clark Porter, Jr., East Liverpool, Ohio; WilliamEarl Moon, Chester, W. Va.

[73] Assignee: Combustion Engineering, Inc.,

Windsor, Conn.

[22] Filed: Sept. 7, 1973 [21] Appl. No.: 395,206

[52] U.S. Cl. 219/; /2; 100/29; 100/33 R; 219/56; 219/91 [51] Int.Cl..... B23k 9/12; B65b 13/04; B65b 13/32 [58] Field of Search 100/2,29, 32, 33 R; 219/56, 80,91

[56] References Cited UNITED STATES PATENTS 181,052 8/1876 DeGray 100/292,233,526 3/1941 Hagedorn et al. 219/91 X 2,438,386 3/1948 Chamberlain100/29 X Primary ExaminerJ. V. Truhe Assistant Examiner-N. D. HerkampAttorney, Agent, or FirmEldon H. Luther 5 7 ABSTRACT A method andapparatus for securely fastening a band to at least one object such as arefractory nozzle for a molten steel pouring ladle. A tab is affixed tothe end of a band and the band is wrapped around the object so as todivide the band into a wrapped section and an unwrapped section, a firstportion of the wrapped section overlying the tab and a second portion ofthe wrapped section. While the tab is restrained against movement in onedirection around the object, the unwrapped section of the band is pulledso as to tighten the band around the object. While the band is held inthis position, automatic welding means indirectly pressure spotweld thetab and the first and second portions of the wrapped section together.

13 Claims, 7 Drawing Figures SHEET PATENTED AUG 5 I975 NE W 6rd mm .32Q3 v8 0 X: 93 9 mm mm v8 m8 v8 on YOQM v2 m8 mm m5 QVRQQNSQQ ND 09 1 y98 k\ Nm\ NW NON Om m2 9 m2 m8 02 mt mm m9 v@ .m/ JC 7 com mm: mm:

vm w 09 m@ v9 mm m m9 mm Wm mm VO\ PATENTEU AUG 5 I975 SHEET METHOD ANDAPPARA' US FOR THE BANDING OF OBJECTS BACKGROUND OF THE INVENTION Thisinvention relates to the art of placing bands around one or more objectsand more particularly to a method and apparatus for tightly wrapping andsecurely fastening bands around such objects including refractorynozzles for molten steel pouring ladles.

In the making of steel, a ladle is required for receiving molten steelfrom the steel-making furnace and transporting the steel from thefurnace to an area in which ingots or castings are made. The moltensteel is then allowed to flow from the ladle into the appropriate moldsor dishes through one or more nozzle openings in the bottom thereof, thenozzle openings being closed and opened by means of a stopper which canbe raised and lowered in the ladle. These ladles must have some means toprevent the molten steel from penetrating to the outer metal sheath ofthe ladle and as such require a refractory lining. Furthermore, nozzlesare required in the bottom of the ladle which are made of a refractorymaterial so as to be capable of withstanding the extreme heatexperienced in the ladle and the erosive action due to the stopper beingraised and lowered. As still further protection by insuring that moltensteel will not pass around the outside surface of the nozzles, arefractory mortar is packed into the openings in the bottom of the ladlebefore the nozzles are inserted. This refractory mortar serves to closeany passages around the outside of the nozzles.

Experience has indicated that most nozzles crack to some extent when themolten steel is received from the steel-making furnace. However, due tothe nature of the ceramic refractory, reheat expansion occurs in whichthe ceramic material bloats and welds or fuses itself back togetheragain. In some instances, this reheat expansion is sufficient to fullyheal the cracks and prevent further breaking up of the nozzles. On theother hand sometimes the reheat expansion is insufficient to heal thecracks. If this occurs, the cracks might spread and the molten steelmight leak around and through the cracked, nozzle, thereby damaging theouter metal sheath of the ladle. This would result in expensive repairwork to the ladle. Accordingly, for steel making facilities whichexperience this insufficient reheat expansion, metal bands have beenusedwhich are tightly wrapped around the nozzles to prevent the nozzles fromtotally breaking apart.

However, disadvantages exist with the prior art procedures for fasteningthese bands to the nozzles. One prior art method involves having one manwrap a band around the nozzle and pulling one end tight while the otherend is held agaist the nozzle surface. Then while the band is tight, asecond man spotwelds the overlapped portions together. As can beappreciated, it is very difficult to make the band tight around thenozzle with such a procedure. Furthermore, it is difficult to achieve aconsistent and dependable weld since the welding procedure depends onthe skill of the operator and the welding apparatus.

Another prior art method involves placing a clip on one end of the band,passing the other endaround the nozzle and through an opening in theclip, pulling the band tight around the nozzle and then crimping theclip. Although this procedure results ina strong, dependable and tightfitting band, the clip is too thick and accordingly it shears away toomuch protective mortar when the nozzle is pushed into place in the ladlebottom.

SUMMARY OF THE INVENTION The present invention overcomes the abovediscussed and other disadvantages by providing a novel method forsecurely fastening bands to an object or group of objects. The methodcomprises first affixing a tab to one end of the band. Next, the objector group of objects is held in position and the band is wrappedtherearound so as to divide the band into a wrapped section and anunwrapped section with a first portion of the wrapped section overylinga second portion of the wrapped section. As the band is wrapped aroundthe object or group of objects, the tab is restrained against movementin a first direction therearound. Next, the unwrapped section of theband is pulled so that the first portion of the wrapped section of theband is moved in the first direction to tighten the band around theobject or group of objects. While the band is held in this pulledposition, the first and second portions of the wrapped section of theband are welded together.

Apparatus for accomplishing this method is also disclosed whichcomprises a table for supporting the object or group of objects and aclamp means for holding the object or group in a fixed position on thetable. Tab restraining means engagable with the tab is provided forrestraining the tab against movement in a first direction around theobject or group. Pulling means are also provided engagable with theunwrapped section of the band for pulling the band in the firstdirection to exert a force on the first portion of the wrapped sectionof the band. Finally welding means is provided for welding together thefirst and second portions of the wrapped section of the band. In thepreferred embodiment, the welding means is an automatic weldingapparatus which is operable when the band has been pulled tight by thepulling means.

Use of such a method and apparatus for securely fastening bands to anobject or group of objects ensures that the band will be tightly wrappedaround the object or group. The use of automatic welding apparatus asopposed to hand welding will result in a more consistent and dependableweld. Furthermore, by using a relatively thin tab, the problem ofshearing away protective mortar when a refractory nozzle is pushed intoplace in a molten steel pouring ladle can be minimized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial side sectionalview of a molten metal pouring ladle showing one use for a banded obect.

FIG. 2 is a front elevational view of the banding apparatus of thepresent invention.

FIG. 3 is a side elevational view of the banding apparatus taken alongline 3-3 of FIG. 2 but shown with an object to be banded in place.

FIG. 4 is a sectional plan view taken along line 4-4 of FIG. 2 but shownwith an object to be banded in place.

FIG. 5 is an enlarged view of a portion of the view of FIG. 4 but withthe cutting means being shown in the cutting position.

FIG. 6 is an elevational view taken along line 6-6 of FIG. 4 showing thepulling means.

FIG. 7 is a side view taken along line 7-7 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,FIG. 1 shows a partial side sectional view of a typical molten steelpouring ladle 12 in which the pouring nozzle 10 is banded in accordancewith the present invention as described hereinbelow. The ladle 12comprises a steel shell or vessel 14 lined interiorally with refractorybrick 16. A nozzle opening 18 is defined in the bottom of the vessel 14by a refractory nozzle block 21 and a cylindrical steel ring 20 whoseinner dimensions are slightly larger than the outer dimension of thenozzle 10. Refractory mortar 22 is typically packed in the nozzleopening 18 and a cylindrically shaped nozzle 10 is slipped into theopening 18 from below the ladle 12. As best seen in FIGS. 1 and 3, thenozzle is made of a refractory material and has a central bore 24therethrough. One end of the nozzle is provided with a reducedcylindrical portion 26 which fits through an opening in the nozzle coverplate 28 which is attached to the steel ring 20 to hold the nozzle 10 inplace in the ladle 12. The other end of the nozzle is provided with aconical surface into which a stopper or plunger 30 may be fitted to stopthe flow of molten steel therethrough out of the ladle 12. For thebanding apparatus described hereinbelow, the nozzle sizes may vary from6-12 inches in diameter although other sizes of cylindrically shapedobjects may be accommodated with slight modifications.

As noted hereinabove, it is sometimes desirable to band the nozzle 10 toprotect against insufficient reheat expansion of the nozzle. When suchbands 32 are used, some of the protective mortar 22 is sheared away asthe nozzle 10 is inserted into the nozzle opening 18. As can beappreciated, it is desirable to minimize the amount of mortar 22 whichis sheared away by the insertion of the nozzle 10. Accordingly thethickness of the band 32 about the circumference of the nozzle 10 mustbe kept to a minimum.

This is accomplished in accordance with the present invention by weldinga steel tab 36 to one end of the band 32 to be wrapped around the nozzle10. The band 32 is then wrapped around the nozzle 10 so as to divide theband 32 into a wrapped section 38 and an unwrapped section 40. A firstportion of the wrapped section 38 which is adjacent to the unwrappedsection 40 overlies or overlaps a second portion of the wrapped section38 which is adjacent to the tab end of the band 32. While the tab 36 isrestrained against movement in a first direction around the nozzle 10,the unwrapped section 40 of the band 32 is pulled so as to move thefirst or overlapping portion in the first direction. The band 32 is heldin this position and the overlapped and overlapping portions are weldedtogether. Preferably, the overlapping portion, the overlapped portionand the tab 36 are all welded together by an automatic welding apparatusso as to provide a strong, dependable and consistent weld.

As an example, by using a /8 inch wide, 0.022 inch thick band 32 and a 1inch square steel tab 36 which is 0.059 inch thick, the maximumthickness of the fastened band 32 outward from the surface of the nozzlecan be made to be approximately A; inch. With the prior art method ofusing a clip and a similar size band, the thickness of the band at thecrimped end can only be minimized to approximately 5 inch. Accordingly,

with the use of the present invention the amount of sheared mortar 34when the nozzle 10 is inserted into the ladle 12 can approximatelybe cutin half, thereby reducing the probability of molten steel leakingthrough the mortar 22 and damaging the steel ladle 12.

The apparatus 50 for tightly wrapping and automatically welding the bandaround the nozzle will now be described with reference to FIGS. 2through 7. As will be apparent hereinbelow, the apparatus 50 can be usedto band any object or group of objects in which it is desirable totightly wrap and securely fasten a band around the object or group ofobjects. However, for simplicity, reference will only be made to thebanding of refractory nozzles 10. The apparatus 50 comprises generally abase 52, an object supporting and holding means 54, and a bandingplatform 56 supported for longitudinal and pivotal movement so that theplatform 56 can be moved longitudinally and laterally relative to thenozzle 10. The banding platform 56 supports the means 58 for positioningand holding the platform laterally relative to the nozzle 10 to bebanded, the tab restraining means 60, the band pulling means 62 and theautomatic welding means 64.

Referring first to FIGS. 2 and 3, the base 52 supports a verticalupright support standard 66 by means of braces 68. The upright supportstandard 66 has a laterally extending portion 70 at its upper end fromwhich is supported the control panel 72 for the banding apparatus 50 anda vertical extending air cylinder 74. The piston rod 76 of the aircylinder 74 is adapted for vertical reciprocal movement and has aclamping pad 78 attached to its end. The air cylinder 74 and clampingpad 78 are aligned and spaced from an object support table 80 which isfixedly supported on the base 52 by standard 82. The nozzle 10 which isto be banded is positioned on the table 80 beneath the clamping aircylinder 74 and the air cylinder 74 may then be actuated to clamp andrigidly hold the nozzle 10 in place. The surface of the table 80 and theclamp pad 78 are preferably made of rubber or other resilient materialso as not to damage the object which is to be supported therebetween.

The base 52 also supports a vertically extending substantiallycylindrical support column 84 for rotation about the central axis of thecolumn. The lower end of the support column 84 is journaled in a bearing86 affixed to the base 52 and the upper end is journaled in a bearing 88which is laterally supported from the upright support standard 66. Aplatform hoist motor 90 having a chain 92 is attached to the upper endof the rotating support column 84. The banding platform 56 is supportedfrom the support column 84 by the chain 92 and is guided forlongitudinal movement therealong by a roller assembly 94 integrallyattached to the platform 56. The roller assembly 94 comprises threepairs of spaced rollers 96 circumferentially arranged and supportedbetween upper and lower annular support plates 98, 100. As shown in FIG.3, the lower support plate 98 is integrally attached to the platformsuch as by welding or bolting. The rollers 96 are adapted to enterguideways 102 defined between longitudinally extending guide rails 104affixed to the outer surface of the rotating support column 84. Byactuation of the hoist motor 90, which is controlled by lever 106, theplatform 56 can be raised or lowered relative to the support column 84and accordingly, relative to the nozzle 10 to be banded which issupported on the table 80.

By virtue of the bearings 86, 88, the support column 84 and platform 56freely pivot as a unit about the axis of the support column 84 to adjustthe lateral position of the platform 56 relative to the supported nozzleas will be apparent hereinbelow.

The banding platform 56 supports all the equipment necessary to securelyfasten bands to cylindrically shaped objects. As can best be seen withreference to FIG. 4, the left side of the platform 56 supports a tabrestraining means 60 and automatic welding means 64. The tab restrainingmeans 60 is of a two-piece construction and acts as a guide and holderfor the tab 36 affixed to the end of the'band 32. One piece is astationary support member 108 which is supported at one end from theplatform 56 such as by welding. The other piece is a guide member 110which is supported from the other end of the support member 108 forpivotal movement about a pin 112 which is positioned in opposed recesses113 in the support and guide members 108, 110. A spring 114 (or twosprings if necessary) holds the two members 108, 110 together and biasesthe guide member 110 for counterclockwise pivotal movement about the pin112. A second pin 116, laterally extending from the support member 108,is adapted to enter a recess 118 in the guide member 110 for guiding thepivotal motion thereof. The guide member 110 is provided with upper andlower spaced feet 120, 122 for engaging the nozzle 10 when the platform56 is pivoted about the axis of a support column 84. As can beappreciated, the guide member 110 will pivot clockwise against the biasof spring 114 to ensure that all four feet 120, 122 engage the nozzle 10as the platform 56 is pivoted to move the guide member 110 intoposition. The vertical spacing between the feet 120, 122 should begreater than the width of the band 32 and less than the diagonal lengthof the tab 36 so that the band 32 can freely pass around the nozzlewhile the tab 36 is restrained. For the lateral spacing between the feet120, 122, a convenient length may be chosen depending on the range ofsizes of the nozzles 10 to be banded.

The three welding guns 124 of the automatic welding means 64 are mountedon the piston rods 128 of three air cylinders 126 which in turn aremounted on the platform in a triangular arrangement as can best be seenin FIG. 3. By actuation of the air cylinders 126 through air lines 130,the electrodes 132, 134, 136 of the welding guns 124 can be moved intocontact with the band 32 and tab 36 to indirect pressure spotweld theband 32 and tab 36. The indirect pressure spotweld technique is utilizedin order to obtain a strong, dependable and consistent weld. Thistechnique involves the use of a welding electrode, a dummy electrode andthe pieces to be welded to complete the circuit to the weldingtransformer (not shown). In the embodiment shown, two welding electrodes132, 136 and one dummy electrode 134 are used to make two indirectpressure spotwelds as indicated by reference numeral 138 in FIG. 7.

The welding procedure is as follows. Two of the air cylinders 126 areactuated to move and press the dummy electrode 134 and one of thewelding electrodes 136 into contact with the tab 36 and band 32respectively. As best seen in FIG. 7, the dummy electrode 134 justcontacts the uppermost corner of the tab 36 (indicated by numeral 140)and the welding electrode 136 contacts the outer overlapping portion ofthe band 32 near one of the two side corners of the tab (indicated by138). Current is then passed from the welding transformer (not shown)through the welding electrode 136, through the overlapping andoverlapped portion of the band 32, through the tab 36 to the dummyelectrode 134 and then back to the welding transformer. Due to thepressure and current applied, the overlapping portion of the band 32,the overlapped portion of the band 32 which is attached to the tab 36and the tab 36 are welded together as indicated by weld contact 38.After the first weld is completed, the welding electrode 136 isretracted and the other welding electrode 132 pressed into contact withthe overlapping portion of the band 32 near the other side corner of thetab 36 and current then passed through the welding electrode 132 to makea second weld. Both the dummy electrode 134 and the other weldingelectrode 132 are then retracted. The required current passing throughthe electrodes 132, 134, 136 and the required pressure applied againstthe band 32 and tab 36 to obtain a strong, dependable weld depends onthe thickness of the band 32 and tab 36, the diameter of the electrodetip which contacts the band 32 and tab 36, and the time of contact. Theuse of this procedure and the determination of these parameters isdeemed to be within the skill of the artisan and accordingly, no furtherrecitation with regard to this is deemed necessary in order to fullyunderstand the present invention.

The means 58 for laterally positioning and holding the platform 56relative to the nozzle 10 is mounted on the right side of the platform56 opposite from the tab restraining means 60 and welding means 64 andcomprises an air cylinder 142 and piston rod 144. The piston rod 144 ofthe air cylinder 142 is provided with a band guide 146 which contactsthe nozzle 10 when the air cylinder 142 is actuated to pivot theplatform 56 about an axis of a support column 84 to move the four feet120, 122 of the tab restraining means 60 into engagement with the nozzle10. The air cylinder 142 and piston rod 144 also serve to restrain theplatform 56 against pivotal movement when the pressure of the weldingguns 124 is applied against the nozzle 10. The air cylinder 142 is fixedto the platform 56 so that the band guide 146 is located approximatelydiametrically opposite the guide member of tab restraining means 60 whenthe nozzle 10 is in position on the table 80. As can be appreciated,this position is approximate in order that the banding apparatus 50 beable to accommodate a variety of nozzle sizes and since precisepositioning is not required. The band guide 146 has a contact surface148 which roughly approximates a portion of the circumference of thenozzle 10. To maintain proper horizontal positioning of the guide 146with respect to the nozzle 10, the guide 146 has one end fixed to theend of the piston rod 144 and the other end fixed to a bar 150 which isslidably positioned in a channeled member 152 adjacent the air cylinder142. In this way, rotation of the piston rod 144 within the air cylinder142 is prevented. When the band 32 which is to be wrapped around thenozzle 10 is being positioned in place for welding, the band 32 willrest on edge on the upper surface of the guide 146 between the nozzle 10and the vertically extending lip 154 of the guide 146.

The band pulling means 62 for pulling the unwrapped section 40 of theband to tightly wrap it around the nozzle is positioned on the backsideof the platform and comprises a rotary air motor 156, a reciprocal aircylinder 158 and two rollers 160, 162. The air motor 156 is verticallymounted on the platform 56 by means of a standard 164. The drive shaft166 of the air motor 156 extends downward and is journaled in a lowercasing 168. A knurled drive roller 160 is mounted on a roller hub 170which is supported from the drive shaft 166 in the slotted opening 172in the lower casing 168. The air cylinder 158 is pivotably. horizontallymounted to the platform 56 by pin 174 and has a piston rod 176 to whichan idler roller support yoke 178 is pin connected by means of a pin 180.An idler roller 162 is pin supported between the two flanges 182 of theidler support yoke 178 by pin 184 and is adapted to engage the knurledroller 160 ofthe air motor 156. As seen in FIG. 4, the idler supportyoke 178 has an extension 186 which is also pin connected to theplatform 56 by pin 188 to ensure proper mating engagement between theidler roller 162 and the knurled roller 160 upon actuation of the aircylinder 158. The band 32 which is to be pulled by the pulling means 62is fed between the knurled roller 160 and the idler roller 162 and theair cylinder 158 actuated to move the idler roller 162 into position toclamp the band 32 between the rollers 160, 162. The air motor 156 canthen be actuated to rotate the knurled roller 160 counterclockwise whichcauses the band 32 to be pulled through the two rollers 160, 162 as aresult of the frictional engagement between the band 32 and the tworollers 160, 162.

A cutting means 190 for removing or severing the un' wrapped section 40from the wrapped section 38 of the band 32 after welding has beencompleted is shown positioned between the tab restraining means 60 andthe automatic welding means 64. The cutting means 190 is mounted to theplatform 56 by means of a bracket 192 at substantially the same verticalelevation as the tab restraining means 60 and the lower two welding guns124. The cutting means 190 comprises an air cylinder 194 with ahorizontally extending piston rod 196 and a cutting blade 198 mounted tothe piston rod 196 by means of a chuck 200. As best seen with referenceto FIGS. 4, and 7, the cutting blade 198 is provided with a verticalcutting edge 202 for contacting and cutting the outer overlappingportion of the band 32 to the left of the two welds 138 as seen in FIG.7. The vertical height of the cutting edge 202 is slightly greater thanthe width of the band 32 but less than the vertical spacing between theupper and lower set of feet 120, 122 of the tab restraining means 60.The extension of the cutting blade 198 outwards from the piston rod 196and the stroke length of the piston rod 196 are adjustable so that thecutting edge 202 will only cut the outer overlying portion of the band32 when the air cylinder 194 of the cutting means 190 is actuated.

Operation of the banding apparatus 50 to tightly wrap and securelyfasten a band 32 about a nozzle 10 will now be described. First, and notdone by the banding apparatus 50, at least one band 32 and morepractically a plurality of bands 32, are assembled with a tab 36attached to one end of each band 32. This can be accomplished forexample by spot welding. As hereinabove noted, it is desirable to usetabs 36 ofa minimum thickness so that the thickness of the welded bandwill be a minimum. With the embodiment shown in-the drawings, the tabs36 are square and the band 32 is welded across two diagonally oppositecorners of a tab 36. Such an arrangement permits the tab to berestrained at the other two corners by the tab restraining means 60while permitting the band 32 attached thereto to pass between the upperand lower sets of feet 120. 122 and then wrap around the nozzle 10.

Next, a nozzle 10 is positioned on the table of the banding apparatus 50and then clamped by the clamping air cylinder 74. The platform 56 isthen positioned vertically with respect to the nozzle 10 by actuation ofthe air hoist motor for the first banding operation and pivoted aboutthe central axis of a support column 84 to move the tab restrainingmeans 60 adjacent the nozzle 10. The backup air cylinder 142 is thenactuated through the control panel 72 to finish lateral adjustment ofthe platform 56 with respect to the nozzle 10 and to hold itthereinplace.

The band 32, with the tab 36 affixed to one end, is then positionedaround the nozzle as follows. First the free end of the band is pulledbetween the upper and lower feet 120, 122 of the tab restraining means60 to position the tab 36 in place adjacent the right side of the guidemember as seen in FIGS. 5 and 7. Next, the free end of the band 32 iswrapped around the nozzle 10 with the lower edge being allowed to reston the band guide 146 of the positioning means 56. This ensures that theband 32 will be horizontal when it is pulled tight since the verticalelevation of the band guide 146 is substantially equal to the verticalelevation of a tab restraining means 60 and the band pulling means 62.The free end is then fed a second time between the upper and lower feet120, 122 to overline the tab 36 and a portion of the wrapped section 38of the band 32. The free end or unwrapped section 40 of the band is thenfed between the knurled roller and the idler roller 162 of the bandpulling means 62 and the air cylinder 158 and air motor 156 actuated. Ascan be appreciated, this action will cause the band 32 to be pulledtight around the nozzle 10 since the tab end of the band 32 isrestrained against movement by the tab restraining means 60 in thedirection that the unwrapped section 40 of the band 32 is being pulled.

While the torque of the air motor 156 is still being applied, the aircylinders 126 associated with the welding gun 124 are sequentiallyactuated through the control panel 72 to weld together the overlappingportion of the band 32 the overlapped portion of the band 32 and the tab36. As hereinabove described, the central dummy electrode 134 is firstpressed into contact with just the tab 36 and then the other electrodes132, 136 pressed into contact and retracted, one at a time, toindirectly pressure spotweld the band portions and tab 36 together. Thecentral dummy electrode 134 is then retracted and the air motor 156 ofthe pulling means 62 stopped. The air cylinder 194 of the cutting meanscan then be actuated to cause the cutting blade 198 to contact just theunwrapped section 40 of the band 32 adjacent the wrapped section 38 tocut or sever the unwrapped section 40.

After the free or unwrapped section 40 of the band 32 is severed fromthe wrapped section 38, the piston rods 176, 144 of the air cylinder 158and the backup air cylinder 142 are retracted. If a second or more bands32 are to be securely fastened to the nozzle 10 at other longitudinalpositions, the air hoist motor 90 can be actuated to adjust thelongitudinal elevation of the platform 56. The banding operations atthese other elevations are then accomplished in a similar manner asdescribed hereinabove. After all bands are securely fastened to thenozzle 10, the clamping air cylinder 72 can be retracted and the nozzle10 removed from the table 80. This completes the operation of thebanding apparatus 50.

It should be noted that it is not necessary that the cut ting blade 198completely sever the band or that the cutting means 190 be used at all.For example, the cutting blade 198 could just dent" the unwrappedsection 40 of the band 32 so that the band 32 is broken upon bending ofthe free end of the band 32. Or, after welding is completed, the freeend could be flexed back and forth to break the band 32.

Of course, as can be appreciated, the size of the air cylinders and airmotors and their operating pressures are dependent upon the specificrequirements of the apparatus 50 and of the size of the objects to be'banded. The determination of these and other parameters is deemed to bewithin the ordinary skill of the artisan and accordingly it is notdeemed necessary to further detail the system described hereinabove withreference to such parameters.

Accordingly there is disclosed herein a novel method and apparatus forsecurely fastening bands 32 to an object or plurality of objects. Use ofa relatively thin tab 36 to which the ends of the wrapped sections 38 ofthe band 32 are welded, results in a strong, dependable and consistentmeans of securing a band to an object. Furthermore, the use of such atab 36 permits the band to be tightly wrapped around the object. Stillfurther, when the present invention is used to band refractory nozzles10, the lateral protrusions at the band joint can be maintained withinacceptable limits as hereinabove noted.

While one preferred method and apparatus in accordance with theinvention has been shown and de scribed, it will be understood that suchis merely illustrative and that changes may be made without departingfrom the scope of the invention as claimed.

What is claimed is: l. A method of securing a band to at least oneobject comprising the steps of:

affixing a tab to one end of said band; holding said object in place;wrapping said band with said tab affixed thereto around said object toprovide a wrapped section including said one end of said band which hassaid tab affixed thereto and an unwrapped section of said band, a firstportion of said wrapped section of said band overlapping both said oneend of said band and said tab; restraining said tab against movement ina first direction around said object; I

pulling said unwrapped section of said band to pull said wrapped sectionin said first direction to tighten said band around said object; and

welding together said first portion of said wrapped section of saidband, said one end of said band and said tab.

2. The method of claim 1 including after the step of welding, the stepof severing said unwrapped section of said band from said wrappedsection.

3. The method of claim 2 wherein the step of restraining said tabagainst movement in said first direction comprises: rigidly, temporarilypositioning a tab restraining means on the surface of said object, saidtab restraining means permitting said band to pass freely between saidtab restraining means and the wall of said object but preventing saidtab from passing therebetween.

4. The method of claim 3 wherein the step of pulling said bandcomprises: guiding said unwrapped section of said band between a driveroller and an idler roller; moving one of said rollers toward the otherof said rollers to clamp said band therebetween; and rotating said driveroller to move said'unwrapped section of said band between said rollers.

5. The method of claim 1 wherein the step of welding together said firstportion of said wrapped section, said one end of said band and said tabcomprises indirectly pressure spotwelding said first portion, said oneend and said tab together.

6. An apparatus for tightly wrapping and securely fastening a bandwrapped around at least one object, the band having a tab affixed to oneend thereof and being divided into a wrapped section which is wrappedaround the object and an unwrapped section, the wrapped section of theband having a first portion which overlaps both the tab and the one endof the band having the tab affixed thereto, the apparatus comprising:

object holding means for holding the object in place;

tab restraining means engagable with said tab for restraining said tabfrom movement in a first direction around the object;

pulling means engagable with the unwrapped section of said band forpulling said wrapped section in said first direction to tighten saidband around the ob ject; and

welding means for welding together the first portion of said wrappedsection, said one end of said band and said tab.

7. The apparatus of claim 6 further including a platform on which saidtab restraining means, said pulling means and said welding means arefixedly supported; and platform support means for supporting saidplatform for relative longitudinal movement and relative lateralmovement with respect to the object.

8. The apparatus of claim 7 further including means for laterallypositioning and holding in place said platform with respect to theobject to properly position said tab restraining means, said pullingmeans and said welding means.

9. The apparatus of claim 8 wherein said platform support meanscomprises a longitudinally extending support column having alongitudinal axis which supports said platform for lateral pivotalmovement about said longitudinal axis and for longitudinal movementtherealong; and wherein said lateral positioning means comprises acylinder means mounted on said platform having a piston rod engagablewith the object for pivoting said platform into position and to hold itthereinplace.

10. The apparatus of claim 9 wherein said tab restraining meanscomprises a guide member and a support member for supporting said guidemember from said platform, said guide member being adapted to contactthe surface of the object when said platform is pivoted into position topermit said band to pass between said guide member and the object and toprevent said tab from passing therebetween.

11. The apparatus of claim 10 wherein said cylinder means is mounted onsaid platform substantially opposed to said guide member and on theopposite side of the object from said guide member; wherein said guidemember has longitudinally spaced feet for contacting the object, thelongitudinal spacing between said feet being greater than thelongitudinal dimension of the wrapped section of said band but less thanthe longitudinal dimension of the tab affixed to said band, and whereinsaid guide member is pivotably mounted on said support member to pivotabout a longitudinal axis when the object is moved into contact withsaid guide member by said cylinder means.

12. The apparatus of claim 11 wherein said pulling means comprises: apair of rollers mounted for rotational movement about parallel axes andadapted to engage the unwrapped section of said band therebetween;

end of said band, and said tab.

1. A method of securing a band to at least one object comprising thesteps of: affixing a tab to one end of said band; holding said object inplace; wrapping said band with said tab affixed thereto around saidobject to provide a wrapped section including said one end of said bandwhich has said tab affixed thereto and an unwrapped section of saidband, a first portion of said wrapped section of said band overlappingboth said one end of said band and said tab; restraining said tabagainst movement in a first direction around said object; pulling saidunwrapped section of said band to pull said wrapped section in saidfirst direction to tighten said band around said object; and weldingtogether said first portion of said wrapped section of said band, saidone end of said band and said tab.
 2. The method of claim 1 includingafter the steP of welding, the step of severing said unwrapped sectionof said band from said wrapped section.
 3. The method of claim 2 whereinthe step of restraining said tab against movement in said firstdirection comprises: rigidly, temporarily positioning a tab restrainingmeans on the surface of said object, said tab restraining meanspermitting said band to pass freely between said tab restraining meansand the wall of said object but preventing said tab from passingtherebetween.
 4. The method of claim 3 wherein the step of pulling saidband comprises: guiding said unwrapped section of said band between adrive roller and an idler roller; moving one of said rollers toward theother of said rollers to clamp said band therebetween; and rotating saiddrive roller to move said unwrapped section of said band between saidrollers.
 5. The method of claim 1 wherein the step of welding togethersaid first portion of said wrapped section, said one end of said bandand said tab comprises indirectly pressure spotwelding said firstportion, said one end and said tab together.
 6. An apparatus for tightlywrapping and securely fastening a band wrapped around at least oneobject, the band having a tab affixed to one end thereof and beingdivided into a wrapped section which is wrapped around the object and anunwrapped section, the wrapped section of the band having a firstportion which overlaps both the tab and the one end of the band havingthe tab affixed thereto, the apparatus comprising: object holding meansfor holding the object in place; tab restraining means engagable withsaid tab for restraining said tab from movement in a first directionaround the object; pulling means engagable with the unwrapped section ofsaid band for pulling said wrapped section in said first direction totighten said band around the object; and welding means for weldingtogether the first portion of said wrapped section, said one end of saidband and said tab.
 7. The apparatus of claim 6 further including aplatform on which said tab restraining means, said pulling means andsaid welding means are fixedly supported; and platform support means forsupporting said platform for relative longitudinal movement and relativelateral movement with respect to the object.
 8. The apparatus of claim 7further including means for laterally positioning and holding in placesaid platform with respect to the object to properly position said tabrestraining means, said pulling means and said welding means.
 9. Theapparatus of claim 8 wherein said platform support means comprises alongitudinally extending support column having a longitudinal axis whichsupports said platform for lateral pivotal movement about saidlongitudinal axis and for longitudinal movement therealong; and whereinsaid lateral positioning means comprises a cylinder means mounted onsaid platform having a piston rod engagable with the object for pivotingsaid platform into position and to hold it thereinplace.
 10. Theapparatus of claim 9 wherein said tab restraining means comprises aguide member and a support member for supporting said guide member fromsaid platform, said guide member being adapted to contact the surface ofthe object when said platform is pivoted into position to permit saidband to pass between said guide member and the object and to preventsaid tab from passing therebetween.
 11. The apparatus of claim 10wherein said cylinder means is mounted on said platform substantiallyopposed to said guide member and on the opposite side of the object fromsaid guide member; wherein said guide member has longitudinally spacedfeet for contacting the object, the longitudinal spacing between saidfeet being greater than the longitudinal dimension of the wrappedsection of said band but less than the longitudinal dimension of the tabaffixed to said band, and wherein said guide member is pivotably mountedon said support member to pivot about a longitudinal axis when theobject is moved into cOntact with said guide member by said cylindermeans.
 12. The apparatus of claim 11 wherein said pulling meanscomprises: a pair of rollers mounted for rotational movement aboutparallel axes and adapted to engage the unwrapped section of said bandtherebetween; and means for rotating one of said rollers to pull saidunwrapped section of said band through and between said rollers.
 13. Theapparatus of claim 12 wherein said welding means comprises at least twowelding guns, one of which has a dummy electrode and the other of whichhas a welding electrode, said two electrodes being mounted on saidplatform for movement into contact with said tab and said bandrespectively to indirectly pressure spotweld together said firstportion, said one end of said band, and said tab.